Gardening to Distraction: Sneaking up on Japanese beetles

Darn it, I was counting on having a handsome, boxer-clad man tiptoeing through my garden again.His wife assures me he will be, only his “bug” patrol this year will be early mornings in her Virginia garden, armed with soapy water in a coffee can and a rolled-up newspaper.

Darn it, I was counting on having a handsome, boxer-clad man tiptoeing through my garden again.

His wife assures me he will be, only his “bug” patrol this year will be early mornings in her Virginia garden, armed with soapy water in a coffee can and a rolled-up newspaper.

His goal is to catch, and drown, every single one of the lovely but invasive Japanese beetles eating his dwarf fruit tree orchard.

If you haven’t been checking your garden lately, the beetles are here. They started hatching in June. They spend several weeks defoliating edible plants, shrubs and trees, and then disappear for another year, only to form as grubs in soil prior to starting a new hatching cycle early summer.

Popillia japonica Newman were first discovered in a southern New Jersey nursery in 1916, imported with iris bulbs before there were plant inspections. In Japan, natural enemies keep the beetles’ populations in check so it’s not a serious plant pest there.

By 1972, U.S. beetle infestations had been reported in 22 states east of the Mississippi River as well as Arkansas, Iowa and Missouri. Since then, the beetles have migrated to southern and western states, costing an estimated $460 million a year to try to control them and prevent major agricultural damage.

I first spotted these insects in my garden four years ago, about the same time that I added two honeybee hives. Since I didn’t want to affect my bees, I started to look at alternatives to chemicals, including traps.

Japanese beetle traps are charged up with pheromones and only work well if they are placed where there are no other beetle sources, or if a whole area, such as a neighborhood uses them.

The traps can work well to assess beetle population numbers. If you put one out when the beetles are flying and you find the trap is filled within a day, you have a problem. If only a sprinkling of beetles show up within a week, you’re good. Those insects may have come in from other areas.

The harder assessment to make is how many grubs you may have per square foot. According to David J. Shetlar, Ohio State University Extension landscape entomologist, Japanese beetle grubs can be sampled in the late summer, August to October, and in the spring, April to June.

If your lawn has brown or dead areas during the normal growing season, survey near the edge of the damage. Otherwise, take several randomly-selected samples throughout the lawn and check for the number of grubs you find.

When I did my sampling, out of eight samples 5-by-8-inches each, I found two grubs. That means the bugs currently having my pink Roses of Sharon for lunch may be casual visitors as opposed to established residents.

Page 2 of 2 - You can discourage Japanese beetles by planting varieties they are not fond of, including ageratum, columbine, begonia, lilies of the valley, coreopsis, foxgloves, delphinium, poppies, lantana, impatiens, nasturtiums and coral bells.

If you do have a serious problem, you can also plant trees that are resistant to Japanese beetles, including red maple, boxwood, hickory, redbud, tulip poplar, dogwood, burning bush, forsythia, ash, holly, juniper, magnolia, spruce, pine, northern red oak, lilac, yew and hemlock.

In the interim, get your coffee can and newspaper ready. When you have it full of sudsy water, sneak up on your plants and, using the rolled up newspaper as a megaphone, say “boo” into the leaves. The beetles will be startled into jumping into the suds and drown. Actually you don’t need the newspaper, they will tend to drop as soon as they see you up close but it does add an element of fun.

The wearing of boxer shorts is purely optional.

Charlotte Ekker Wiggins is a certified gardener sharing gardening tips in a changing climate at http://www.gardeningcharlotte.com. Copyright 2013 used with permission by Rolla Daily News - St. James Leader Journal - Waynesville Daily Guide. All rights reserved. This material may not be published, broadcast, rewritten or redistributed. Contact Charlotte at chargardens@gmail.com.